Somatosensory and affective contributions to emotional, social, and daily functioning in chronic pain patients.

Objective: The present study tested the independent and interactive contributions of the somatosensory component of pain (pain intensity) and the affective component of pain (pain unpleasantness) on emotional, social, and daily functioning in chronic pain patients.

Subjects: Participants were 472 patients seeking treatment for chronic orofacial pain. Mean age of the sample was 46.0 years (standard deviation [SD] = 14.67, range 18-78), with 82.2% female. Average pain duration at the time of initial appointment was 75.7 months (SD = 106.66).

Methods: Participants completed self-report measures of pain intensity, unpleasantness, and functional outcomes at the time of their first appointment. These data were later extracted from participant's de-identified medical records. Multivariate linear regression was used to test the interaction of pain intensity and unpleasantness on outcome measures of emotional, social, and daily functioning.

Results: Results revealed that pain intensity contributed to poorer functional outcomes but higher levels of social support even after controlling for pain unpleasantness. After controlling for pain intensity, unpleasantness was associated with higher pain interference and affective distress. There was also pain intensity by unpleasantness interaction on pain interference. Specifically, at lower levels of pain unpleasantness, changes in pain intensity produced greater changes in pain interference than they did at higher levels of pain unpleasantness.

Conclusions: Results suggest that both intensity and unpleasantness contribute unique variance to functional outcomes. The results highlight the importance of interventions that not only try to reduce pain levels but also reduce levels of pain unpleasantness.